This study will support the indication for use of BRL 49653C in combination with sulphonylureas in the management of patients with NIDDM. It will determine if the combination of the two classes of drug produces an additive effect on metabolic control. Additionally, this study together with another study(study 079 which will investigate the effect of adding BRL 49653C to patients inadequately controlled on MAXIMAL doses of glyburide) will provide guidance as to the optimal time to use the combination of BRL 49653C and sulphonylureas in the management of patients with NIDDM.